JP5109569B2 - Front bumper structure - Google Patents

Description

  The present invention relates to a front bumper structure in a vehicle such as an automobile, and more particularly to a front bumper structure excellent in a pedestrian protection function.

Recently, various proposals have been made to protect a pedestrian when a vehicle collides with the pedestrian.
For example, Patent Document 1 describes an airbag that is inflated on a hood when a collision with a pedestrian, a mechanism that lifts a rear portion of the hood and tilts the hood at a predetermined angle, and the like. However, these mechanisms require an operating mechanism such as an inflator and detection means for detecting a pedestrian collision for the operation of the operating mechanism. Therefore, in order to realize these pedestrian protection functions, the vehicle weight is increased and a considerable increase in cost cannot be avoided. Moreover, these pedestrian protection functions are intended to prevent a pedestrian riding on the hood from colliding with the windshield and the like, and do not reduce the load on the legs of the pedestrian.

  On the other hand, in recent years, attention has been focused on trying to improve the pedestrian protection function by reducing the load on the legs of the pedestrian. That is, the impact at the time of collision is applied to the pedestrian's leg below the knee, that is, the lower part of the knee is properly supported to protect the part above the knee. For example, Patent Document 2 proposes a technique that achieves this with a simple configuration. In this conventional structure, as shown in FIG. 7, a buffer member 32 made of synthetic resin is attached to the lower front portion of the bumper beam 31. The buffer member 32 includes an upper leg portion 32 a and a lower leg portion 32 b that protrude forward from the front surface of the bumper beam 31, and a bridge portion 32 c that connects the leg portions 32 a and 32 b on the front side away from the bumper beam 31. . The upper leg portion 32 a is in contact with the front surface of the bumper beam 31. The lower leg portion 32 b is in contact with the front surface and the lower surface of the bumper beam 31. A bumper fascia 33 is disposed so as to cover the bumper beam 31 and the buffer member 32.

  However, in the front bumper structure of Patent Document 2, since the buffer member 32 is attached to the front surface of the bumper beam 31, when the vehicle collides with the pedestrian, the load reducing effect on the leg of the pedestrian is It is limited to vehicles with a low installation position of the bumper beam 31. In a vehicle with a high installation position of the bumper beam 31, when the vehicle collides with a pedestrian, naturally, a large load is applied to the pedestrian's knee or an upper portion thereof.

In order to cope with such a problem, for example, a front bumper structure as shown in FIG. 8 has also been proposed. In this conventional structure, a first buffer member 34 is attached to the front surface of the bumper beam 31. A second buffer member 36 is fastened and fixed to the lower surface of the rectangular frame-shaped radiator support 35 by a plurality of bolts 37 so as to be positioned below the first buffer member 34. When the vehicle collides with a pedestrian, the second cushioning member 36 appropriately supports the lower knee while buffering the lower knee of the pedestrian's leg so as to reduce the load on the leg.
JP 2006-273064 A JP 2007-145159 A

  By the way, in such a conventional front bumper structure, the second buffer member 36 is required to have flexibility for absorbing energy at the time of collision and a certain degree of rigidity necessary to properly support the knee. However, in this conventional structure, although the center portion of the second buffer member 36 is fixed to the radiator support 35, the radiator support 35 is not a strength carrying member of the vehicle body, so the second buffer member 36 is attached to the second support member 36. Rigidity is poor and, therefore, sufficient rigidity required to properly support the lower knee cannot be ensured. In order to ensure rigidity, it is possible to change the radiator support 35 or the structure around it. However, in recent years, the common use of platforms is progressing, and such a change that inhibits the common use. Is difficult.

  The present invention has been made paying attention to such problems existing in the prior art. An object of the present invention is to provide a front bumper structure capable of effectively improving the rigidity of the buffer member without changing the vehicle structure and effectively exhibiting pedestrian protection.

In order to achieve the above object, the invention according to claim 1 is directed to a front bumper structure in which a first buffer member and a second buffer member extending in a vehicle width direction are provided at an upper portion and a lower portion of a front portion of a vehicle body, respectively. The rear side upper surface of the center portion in the vehicle width direction of the second buffer member is attached to the lower surface of the structural member of the vehicle body, and the rear surfaces of both end portions in the vehicle width direction are supported by being brought into contact with the front surfaces of the frames on both sides of the vehicle body. To do. Here, the frame refers to a frame provided for the purpose of reinforcing the vehicle body, and the structural material refers to a frame provided for other purposes for holding a radiator or the like.

The invention according to claim 2 is a front bumper structure in which a first buffer member and a second buffer member extending in the vehicle width direction are provided at an upper portion and a lower portion of the front portion of the vehicle body, respectively, and The rear upper surface of the vehicle body is attached to the lower surface of the structural member of the vehicle body, the rear surfaces of both ends in the vehicle width direction of the second buffer member are attached to the front surfaces of the frames on both sides of the vehicle body, The structural member that is supported on the front surface and to which the second buffer member is attached and the front surface position of the frame are relatively displaced in the vehicle front-rear direction .
According to a third aspect of the present invention, in the first or second aspect, the second buffer member has a higher hardness than the first buffer member .

A fourth aspect of the present invention provides the projection according to any one of the first to third aspects, wherein a projecting portion and a thick portion are formed at an upper portion and a lower portion of both ends of the second buffer member in the vehicle width direction, respectively. A first contact surface that is supported by contacting the front surface of the frame on the rear surface of the frame, and a second contact surface that is supported by contacting the lower surface of the frame on the upper surface of the rear portion of the thick portion. It is provided.

The invention of claim 5 is characterized in that, in claim 4 , the upper edge of the projecting portion is inclined forward and downward.
The invention of claim 6 is characterized in that, in claim 4 or 5 , the lower surface front end of the thick part is inclined upward.

The invention of a seventh aspect is characterized in that, in any one of the first to sixth aspects, an attachment portion for an under cover is formed at both ends of the second buffer member.
As described above, since the second buffer member of the present invention is supported on the front surface of the vehicle body frame at both ends thereof, the structural material such as the radiator support can be redesigned in order to improve the rigidity of the second buffer member. It is not necessary to do. Therefore, the rigidity improvement of the 2nd buffer member provided in the low position can be achieved, without inhibiting commonality of a platform. And when the vehicle provided with this front bumper structure collides with a pedestrian, the 2nd buffer member provided in the lower part will hit under the knee of a pedestrian's leg part with shock absorption. In this case, since the rear end surface of the second buffer member is supported by the front surfaces of the frames on both sides of the vehicle body, moderate rigidity can be given to the second buffer member. Therefore, the 2nd buffer member can support a pedestrian appropriately under a knee appropriately, and can reduce load to a pedestrian's leg.

  As described above, according to the present invention, it is possible to appropriately improve the rigidity of the buffer member without changing the vehicle structure, and to exhibit the effect that the pedestrian protection can be effectively exhibited.

Below, one Embodiment of the front part bumper structure provided in the front part of the vehicle body is described based on FIGS.
As shown in FIGS. 1 to 3, a bumper beam 12 made of an aluminum alloy or the like is provided between a pair of support legs 13 between the front ends of a pair of chassis members 11 serving as a frame responsible for the main reinforcing function of the vehicle body on both the left and right sides of the vehicle body. It is erected and fixed so as to extend in the vehicle width direction. A first cushioning member 14 made of a cushioning material such as foamed polystyrene is attached to the front surface of the bumper beam 12 so as to extend in the vehicle width direction.

  Between the lower ends of the front ends of the chassis members 11, a cross member 15 as a frame having a reinforcing function is installed and fixed via connection means such as a bolt (not shown). A square frame-shaped radiator support 16 as a structural material is placed and fixed on the cross member 15 between the chassis members 11. A second buffer member 17 made of FRP (glass fiber plastic) is disposed on the lower surface of the radiator support 16 so as to extend substantially parallel to the left-right direction at a position below the first buffer member 14. The second buffer member 17 is formed with higher hardness than the first buffer member 14.

  As shown in FIG. 4, the second buffer member 17 protrudes forward and has a substantially flat plate-like main body portion 19 extending in the vehicle width direction, and upwards on the upper surface rear portions of the left and right ends of the main body portion 19. Projected side projections 20 having a substantially triangular shape, a thick portion 21 formed so as to project rearward and laterally at the rear of the lower surface of the left and right ends of the main body 19, and both sides of each thick portion 21 And an attachment portion 22 formed to be extended. A raised first contact surface 20 a is formed on the rear surface of the protrusion 20. Moreover, the upper edge 20b of the protrusion 20 is inclined forward and downward. A front-facing inclined surface 21a is formed at the front end of the lower surface of both thick portions 21, and a substantially horizontal second contact surface 21b is formed on the rear upper surface. As shown in FIG. 3, the rear end edge of the upper surface of the main body 19 of the second buffer member 17 is attached to the lower surface of the radiator support 16 by the bolt 18 from below.

  As shown in FIGS. 2 and 3, the rear end surface of the main body portion 19 of the second buffer member 17 is supported in contact with the front surface of the cross member 15. In addition, the first contact surfaces 20 a of both projecting portions 20 are supported in contact with the front surfaces of the chassis members 11 and the cross members 15 on both sides. Further, the second contact surfaces 21 b of both thick portions 21 are in contact with the inner surface of the recess 15 a formed on the front lower surface of the cross member 15, that is, the lower surface. The rear end surface of the thick portion 21 is supported in contact with the forward-facing surface of the recess 15a. In this state, as shown in FIGS. 1 and 2, both thick portions 21 are fastened and fixed to the cross member 15 from below by a pair of bolts 23.

  As shown in FIGS. 1 to 3, a bumper fascia 24 made of a synthetic resin covering the front surfaces of the first buffer member 14 and the second buffer member 17 is provided at the front portions of the chassis members 11. Is attached through. Accordingly, the first and second buffer members 14 and 17 are disposed on the back side of the bumper fascia 24. The second buffer member 17 is harder than the bumper fascia 24.

  An under cover 25 having a function of mudguard or the like is attached to both the attachment portions 22 of the second buffer member 17 by bolts or the like (not shown). 2 and 3 indicate a ventilation opening formed in the bumper fascia 24.

Next, the operation of the front bumper structure configured as described above will be described.
Now, when a vehicle equipped with this front bumper structure collides with a pedestrian, the bumper fascia 24 is elastically deformed and the first buffer member 14 is deformed to absorb the impact. The second cushioning member 17 provided below the first cushioning member 14 appropriately supports the pedestrian's leg below the knee while absorbing the shock. In this case, the second buffer member 17 is supported in contact with the front surface of the cross member 15 and the chassis members 11 on both sides at the first contact surfaces 20a of the protrusions 20 on the left and right sides. At the same time, the second contact surface 21 b of the thick portion 21 is abutted and supported on the lower surface of the cross member 15. The body portion 19 of the second buffer member 17 is fixed to the lower surface of the radiator support 16 by a plurality of bolts 18, and both thick portions 21 are fixed to the lower surface of the cross member 15 by a pair of bolts 23. Yes.

  Therefore, the 2nd buffer member 17 is maintained in the state hold | maintained appropriately in the front-back direction and an up-down direction, Therefore, the rotation of the direction which the front-end part of the main-body part 19 moves below is also stopped. That is, at the time of a collision with a pedestrian, a backward force and a clockwise rotational force in FIG. 2 act on the second buffer member 17 through the deformation of the bumper fascia 24. At this time, the backward force is mainly the contact between the front surface of the chassis member 11 and the cross member 15 and the first contact surface 20a, and the clockwise force is the second contact with the lower surface of the cross member 15 and the radiator support 16. It is regulated by contact between the contact surface 21 b and the upper surface of the main body 19. Therefore, the second buffer member 17 can obtain an appropriate rigidity. Therefore, the second cushioning member 17 can effectively support the lower knee portion of the pedestrian's leg.

Therefore, the front bumper structure of this embodiment exhibits the following effects.
(1) The protrusion 20 is provided on the second buffer member 17 and the protrusion 20 is supported by the chassis member 11 and the cross member 15, and the thick portion 21 is provided on the second buffer member 17. The part 21 was supported on the lower surface of the cross member 15, and the thick part 21 was fixed to the cross member 15 with bolts. Therefore, as described above, the rigidity of the second buffer member 17 can be ensured, and it is not necessary to change the design of the structural material such as the radiator support 16 in order to improve the rigidity. Therefore, the rigidity improvement of the 2nd buffer member 17 provided in the low position can be achieved, without inhibiting commonality of a platform.

  (2) The second cushioning member 17 provided at a low position and having appropriate rigidity in the front-rear direction and the rotational direction appropriately supports the knee below the pedestrian's leg while absorbing shock, and a portion above the knee Is sufficiently absorbed by the deformation of the first buffer member 14. For this reason, the load with respect to a pedestrian can be reduced effectively. When the vehicle collides with a person other than a pedestrian, for example, against a road structure, the second buffer member 17 is greatly deformed to absorb the collision energy and reduce the impact. Incidentally, FIG. 5 shows the result of comparing the characteristics of the front bumper structure of this embodiment and the conventional front bumper structure shown in FIG. FIG. 5 shows the amount of displacement of the second buffer member with respect to the load applied to the central portion in the vehicle width direction of the second buffer member at the low position obliquely from above. That is, in the conventional front bumper structure, the amount of displacement increases rapidly as the load increases, and the amount of displacement decreases rapidly when the load reaches a certain value. On the other hand, in the front bumper structure of the embodiment, the displacement is sustained. Therefore, the front bumper structure of the embodiment has a wide range in which the buffer function is effectively exhibited with respect to the load.

  (3) In order to form the first and second contact surfaces 20a and 21b, the protruding portion 20 and the thick portion 21 are formed on the upper and lower portions of both ends in the vehicle width direction of the second buffer member 17, respectively. . Therefore, the main body 19 that occupies most of the length of the second buffer member 17 can be formed thin, which can contribute to reducing the vehicle weight.

  (4) Since the upper edge 20b of the protruding portion 20 is inclined forward and downward, the protruding portion 20 does not hit the pedestrian strongly at the time of collision with the pedestrian. For this reason, the load with respect to a pedestrian can further be reduced.

  (5) An upwardly inclined surface 21 a is formed at the front end of the lower surface of both thick portions 21 of the second buffer member 17. For this reason, when the vehicle moves from a flat road to an uphill slope, it is possible to prevent the lower surface of the second buffer member 17 from coming into contact with the slope road and being damaged.

  (6) Since the attachment portions 22 are formed at both end portions of the second buffer member 17, the under cover 25 for mudguard or the like can be attached to the attachment portions 22. Accordingly, since the second buffer member 17 also has a function of attaching the under cover 25, the number of parts of the vehicle can be reduced.

(Example of change)
In addition, this embodiment can also be changed and embodied as follows.
As shown in FIG. 6, in the configuration in which the cross member 15 extends forward and the radiator support 16 is placed and fixed on the upper surface, the second contact surface of the thick portion 21 of the second buffer member 17 21 b is brought into contact with the lower surface of the cross member 15 and fixed with bolts 18. Even if comprised in this way, the effect | action and effect similar to the said embodiment can be acquired. Therefore, in this configuration, the main body 19 of the second buffer member 17 is not fixed to the radiator support 16.

-The mounting part 22 for the under cover 25 should be omitted.
-Changing the material of the second buffer member 17. For example, use an aluminum hollow material that performs a buffering function by deformation.

  The first contact surface 20 a of the second buffer member 17 is separated from the front surface of the cross member 15. Alternatively, the first contact surface 20 a is separated from the front surface of the chassis member 11. That is, the first contact surface 20 a of the second buffer member 17 may be in contact with either the front surface of the cross member 15 or the front surface of the chassis member 11.

  The omission of the first buffer member 14 made of the bumper beam 12 and the foamed polystyrene on the front surface thereof is omitted. Accordingly, in this case, the upper side of the bumper fascia 24 constitutes the first buffer member.

The front view which shows the front bumper structure of one Embodiment. Sectional drawing in the 2-2 line of FIG. The fragmentary sectional view in the 3-3 line of FIG. The perspective view of the 2nd buffer member in the front part bumper structure of FIG. The characteristic view which shows the relationship of the load with respect to the displacement amount of a 2nd buffer member. Sectional drawing which shows a modification. Sectional drawing which shows the conventional front bumper structure. The front view which shows another conventional front bumper structure.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Frame, 12 ... Bumper beam, 14 ... 1st buffer member, 15 ... Cross member, 16 ... Radiator support, 17 ... 2nd buffer member, 18 ... Bolt, 19 ... Main-body part, 20 ... Projection part, 20a ... 1st Contact surface, 20b ... upper edge, 21 ... thick portion, 21a ... inclined surface, 21b ... second contact surface, 23 ... bolt, 22 ... mounting portion, 24 ... bumper fascia.

Claims (7)

In the front bumper structure in which the first buffer member and the second buffer member extending in the vehicle width direction are provided at the upper part and the lower part of the front part of the vehicle body, respectively.
The rear side upper surface of the center portion in the vehicle width direction of the second buffer member is attached to the lower surface of the structural member of the vehicle body, and the rear surfaces of both ends in the vehicle width direction are supported by contacting the front surfaces of the frames on both sides of the vehicle body. And front bumper structure. In the front bumper structure in which the first buffer member and the second buffer member extending in the vehicle width direction are provided at the upper part and the lower part of the front part of the vehicle body, respectively.
The rear upper surface of the center portion in the vehicle width direction of the second buffer member is attached to the lower surface of the structural member of the vehicle body, and the rear surfaces of both end portions in the vehicle width direction of the second buffer member are attached to the front surfaces of the frames on both sides of the vehicle body. Support the rear surface of both ends in the width direction on the front surface of the frame,
A front bumper structure characterized in that the structural member to which the second buffer member is attached and the position of the front surface of the frame are relatively displaced in the vehicle front-rear direction. The front bumper structure according to claim 1, wherein the second buffer member has a higher hardness than the first buffer member. A first abutting surface that is supported by being in contact with the front surface of the frame on the rear surface of the projecting portion by forming a projecting portion and a thick portion at the upper and lower portions of both ends in the vehicle width direction of the second buffer member. 4, and a second abutting surface that is supported by abutting against the lower surface of the frame is provided on the upper surface of the rear portion of the thick portion. Front bumper structure. The front bumper structure according to claim 4, wherein an upper edge of the protruding portion is inclined forward and downward. The front bumper structure according to claim 4 or 5, wherein the front end of the lower surface of the thick part is inclined upward. The front bumper structure according to any one of claims 1 to 6, wherein attachment portions for undercovers are formed at both ends of the second buffer member.

Images